Piston Free Stirling Cycle Engine

ABSTRACT

The present invention provides a piston-free Stirling cycle engine by incorporating the operation of a Stirling cycle within a rotary engine. The engine consists of a rotor located within a housing. The rotor is circular in shape and has chambers extending into the rotor and positioned around the periphery of the rotor. The rotor is connected to a driver and resides within the housing. A blade extends from each chamber and contacts an inner surface of the housing. Compartments are formed between adjacent extended blades and contain gas. The housing is of a unique shape consisting of four sections having different arcs. A first quarter section and a second quarter section have distinct radii lengths and a common center. The common center is the point about which the rotor rotates. A third quarter section and a fourth quarter section, positioned between the first and second quarter sections, are each connected on opposite sides of the housing and have distinct centers and identical radii lengths. The unique housing configuration provided by these four distinct quarter circles allows for a more efficient Stirling cycle as the rotor and thus the compartments rotate. As the Stirling cycle requires the alternating application of high temperatures and low temperatures, a heating element may be placed on a first section of the housing and a cooling element may be placed facing the section opposing the first section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to energy conversion devices and, more specifically, to Engines based on the thermodynamic cycle known as the “Stirling cycle”.

2. Description of the Prior Art

Currently, one of the most commonly employed engines is the internal combustion engine. Combustion is the process of burning a fuel gas mixture. In an internal combustion engine combustion takes place within the housing of the engine. This type of engine is widely used, especially within most current cars and trucks. In contrast, combustion in an external combustion engine, such as the steam engine, takes place outside the engine. Internal combustion engines operate on the thermodynamic cycles known as “Otto Cycle” or “diesel cycle”. Internal combustion engines generally use a reciprocating piston configuration to achieve the required thermodynamic processes of the “Otto Cycle”. A piston is displaced within the cylinder achieving intake, compression, combustion and exhaust of the air/fuel mixture. Improvements have been introduced to the internal combustion piston engine based on the “Otto Cycle” by replacing pistons with a rotor that rotates within a housing. This engine is known as the “Wankel engine”.

The rotary engine is made up of a rotor and housing with three distinct compartments formed between the rotor and housing. Each compartment or chamber goes through the four thermodynamic processes of the “Otto Cycle” as the rotor moves through one full revolution. The rotor is triangular in shape and has three corners and three faces. Each compartment is defined by at least one tip of the rotor and the housing. The three compartments each complete the four phases of the combustion cycle during a complete revolution. In one complete revolution of the rotor, there will be three power strokes. The rotor follows a path similar to that created with a Spiro graph when rotating about the housing. This path keeps each of the three peaks of the rotor in contact with the housing, creating a chamber of gas between adjacent peaks and the housing. As the rotor moves around the chamber, each of the three volumes of gas alternately expands and contracts. It is this expansion and contraction that draws air and fuel into the engine, compresses air and fuel and produces power as combustion takes place. Exhaust from the combustion is then expelled. A rotary engine is only similar to a piston engine in that it is an internal combustion engine based on the “Otto cycle”. The air/fuel mixture is drawn into the housing, compressed, expanded by combustion and then expelled to the outside of the engine. However, a rotary engine takes advantage of the efficiency of a rotating motion instead of the reciprocating motion of cylinders to perform the required operation. In a reciprocating motion, a piston moves in one direction, decelerates, and comes to a stop in order to accelerate again in the opposite direction.

The “Stirling engine”, also known as a heat engine, operates on the “Stirling Cycle”. The Stirling cycle is inherently more efficient than the “Otto cycle” but a commercially successful and viable Stirling engine has not yet been introduced as all Stirling engines have been based on a modified piston engine design.

The gas within a Stirling engine goes through the following thermodynamic processes:

1. Constant Volume Heating;

2. Isothermal Heating and Expansion;

3. Constant Volume Cooling; and

4. Isothermal Cooling and Compression.

The Air/Fuel mixture is not introduced within the Stirling engine, as in the combustion engine. Instead heat is generated externally and exchanged with gas within the engine. The gas is therefore sealed within the housing of the engine with no open exchange of air with the area outside the housing. A heat exchange takes place in order to provide heat to the engine in phase 2, “Isothermal Heating and expansion”, of the cycle and another heat exchange takes place to remove heat from the engine in phase 4, “Isothermal Cooling and Compression”. An internal heat transfer process takes place in phase 1, “Constant Volume Heating”, and phase 3, “Constant Volume Cooling”, wherein heat is exchanged between two compartments. The higher temperature gas in within phase 3 of “Constant Volume Cooling” gives off heat which is exchanged with the gas that is going through phase 1 of “Constant Volume Heating”. There is no exchange of gas but only a heat exchange taking place internally within phase 1 and phase 3. Stirling engines are flexible and many heat sources can be incorporated such as combustion of a variety of fossil fuels, solar, geothermal, thermal battery storage, nuclear etc. The “Stirling engines” produce power indiscriminately of the heat source. However, unlike the internal combustion engine, the Stirling engine does not rely on the ability of certain gasses to combust upon ignition to drive the cylinders. Rather, the Stirling engine relies on different processes; mainly the relation of volume and temperature. These properties help in the realization of an engine based on the Stirling cycle.

In the first phase, gas is heated isothermally, causing the gas to increase in pressure and expand, thus increasing the volume of the gas. In the second phase, the gas is cooled while at a constant volume. This cooling is accomplished internally by exchanging heat with the portion of gas passing through the fourth phase of constant volume heating. In the third phase, the gas is cooled isothermally and compressed, reducing the volume of the gas. The isothermal cooling process requires removal of heat and exchange with environment. In the fourth and final phase, the gas is heated at a constant volume by internally exchanging heat with the portion of gas that is going through the second phase of constant volume cooling, thereby increasing the pressure of the gas.

The method employed by the engine according to invention principles allows reproduction of the Stirling cycle within a rotary motion without the use of reciprocating pistons. In this way more power can be produced within a single revolution than with the piston engine. Additionally, there are other benefits associated with Rotary engines such as fewer moving parts, better heat exchange within the hot side and the cold side and better internal heat exchange between both constant volume processes. Therefore, it would be beneficial to implement the methods of the Stirling cycle, usually implemented in a piston configuration, within the configuration of a rotary engine. Thus, there is a need for an efficient piston-free Stirling cycle engine.

SUMMARY OF THE INVENTION

An energy conversion device is provided according to invention principles. The device includes a housing. The housing includes a first section of increasing volume and a second section of decreasing volume. The second section is positioned on a side of the housing opposite the first section. A third section of constant volume is positioned between a first end side of the first section and a first end side of the second section. A fourth section of constant volume is positioned between a second end side of the first section and a second end side of the second section on a side of the housing opposite the third section.

Additionally, a method for converting thermal energy into mechanical energy by rotating a rotor within a housing is provided according to invention principles. The rotor forms a plurality of chambers within the housing. The method includes providing and sealing gas within each of the plurality of chambers. Heat is applied to a first set of chambers positioned within a first section of the housing. The gas within the first set of chambers is then expanded. The rotor is rotated in response to the expansion of the gas within the first set of chambers. The rotation of the rotor causes the first set of chambers to rotate into a second constant volume section of the housing and a second adjacent set of chambers to rotate into the first section where the gas therein is heated. Upon cooling of the gas within the first set of chambers, the first set of chambers are caused to rotate into a third decreasing volume section of the housing, the second set of chambers rotates into the second section and a third set of chambers adjacent the second set of chambers rotates into the first section where the gas therein is heated. Upon isothermal heating of the gas within the third set of chambers, the first set of chambers is caused to move into a fourth constant volume section of the housing, the second set of chambers moves into the third section, the third set of chambers moves into the second section and a fourth set of chambers positioned between the third set of chambers and first set of chambers rotates into the first section where the gas contained therein is heated. Upon constant volume heating of the fourth set of chambers, the first set of chambers is caused to rotate back into the first increasing volume section of the housing, the second set moves into the fourth section, the third set moves into the third section and the fourth set moves into the second section.

Further, a method for providing cooling or heating is provided according to invention principles. This method operates according to the principles of the “reverse Stirling cycle”. The rotor forms a plurality of chambers within the housing. The method comprises providing gas sealed within each of a plurality of chambers. The gas within a first set of chambers positioned within a first section of the housing is expanded. This expansion requires the absorption of heat from outside the housing, thus providing a cooling effect. The rotor is rotated. The rotation of the rotor causes the first set of chambers to rotate into a second constant volume section of the housing and an adjacent set of chambers to rotate into the first section to be expanded. Upon expanding the second set of chambers, the first set of chambers is caused to rotate into a third decreasing volume section of the housing, the second set of chambers rotates into the second section and a third set of chambers adjacent to the second set of chambers rotates into the first section to be expanded. The set of chambers moved into the decreasing volume section are compressed, thus releasing heat to the area outside the housing and providing a heating effect. Upon expanding the gas within the third set of chambers, the first set of chambers is caused to rotate into a fourth constant volume section of the housing, the second set of chambers rotates into the third section, the third set of chambers rotates into the second section and a fourth set of chambers adjacent to the third set of chambers rotates into the first section to be expanded. Upon expanding the fourth set of chambers, the first set of chambers rotates into the first increasing volume section of the housing, the second set of chambers rotates into the fourth section, the third set of chambers rotates into the third section and the fourth set of chambers rotates into the second section.

Even further, a piston-free Stirling cycle engine is provided according to invention principles by incorporating the operation of a Stirling cycle within a rotary engine. The engine includes a rotor located within a housing. The rotor is circular in shape and has chambers or vanes extending into the rotor and positioned around the periphery of the rotor. The rotor is connected to a driver and resides within the housing. A blade at least partially extends from each vane and contacts an inner surface of the housing. Compartments are formed between adjacent extended blades, the housing and rotor. Each compartment contains a gas therein. The housing is of a unique shape consisting of four sections having different arcs or four independent quarter circles. A first quarter section and a second quarter section have distinct radii lengths and a common center. The common center is the point about which the rotor rotates. A third quarter section and a fourth quarter section, positioned between the first and second quarter sections, form opposing sides of the housing and have distinct centers and identical radii lengths. The unique housing configuration provided by these four distinct quarter circles allows for realization of the Stirling cycle as the rotor and thus the compartments rotate. As the Stirling cycle requires the alternating application of high temperatures and low temperatures, a heating element may be placed on a first section of the housing and a cooling element may be placed on the opposing side of the housing.

It is an object according to invention principles to provide a piston-free Stirling cycle engine having a unique shape and allowing the more efficient Stirling cycle to be realized with better thermal and volumetric efficiency.

The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawings, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawings, like reference characters designate the same or similar parts throughout the several views.

The following detailed description is, therefore, not to be taken in a limiting sense, and the scope according to invention principles is best defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which:

FIGS. 1 a, 1 b, 1 c are an illustrative view of the housing of the Piston-free Stirling Cycle Engine according to invention principles;

FIG. 2 is an illustrative view of the housing of the Piston-free Stirling Cycle Engine according to invention principles;

FIG. 3 is an illustrative view of the rotor and housing of the Piston-free Stirling Cycle Engine according to invention principles;

FIGS. 4 a and 4 b are illustrative views of the rotor, housing and blades of the Piston-free Stirling Cycle Engine according to invention principles;

FIG. 5 is an illustrative views of the rotor, housing and blades of the Piston-free Stirling Cycle Engine according to invention principles;

FIG. 6 is an illustrative view of the Piston-free Stirling Cycle Engine according to invention principles;

FIG. 7 is an illustrative view of the Piston-free Reverse Stirling Cycle refrigeration engine according to invention principles;

FIG. 8 is a flow diagram of the Piston-free Stirling Cycle Engine according to invention principles; and

FIG. 9 is a flow diagram of an alternate embodiment of the Piston-free Stirling Cycle Engine according to invention principles.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Conventional rotary engines include a housing having an oval shape, more specifically, an epitrochoid shape. This shape is derived so that a triangular shaped rotor will have each of its corners touching a face of the housing at all times. The present system includes a housing having a shape containing four unique quarter circles. The properties associated with the four unique quarter circles are conducive to performing the four thermodynamic processes of the Stirling cycle. A first pair of opposing quarter sections have a common center and distinct radii while a second pair of quarter sections have distinct centers and identical radii. A rotor is positioned within the housing formed by the first and second pair of quarter sections. The rotor includes a plurality of vanes positioned around a periphery thereof. A blade movably is positioned within each vane.

According to invention principles the rotor rotates about the common center of the first pair of opposing quarter sections. As the quarter sections have different radii, the blades extend from and retract into the slots of the rotor so that the ends of two diametrically opposed blades have a fixed and constant dimension throughout the full rotation and thus the ends of two diametrically opposed blades are constantly in contact with the inner surface of the housing throughout the full rotation. Gas is provided within the area between blades, housing and rotor and the sealed gas rotates with the rotor and blades. Each quarter of the housing has a different volume. Therefore, as the areas of gas rotate within the housing, the volume of each area in which the gas is contained changes based upon the quarter of the housing in which the gas is positioned. This variation in volume contributes to the four stages of the Stirling cycle. The first stage of the Stirling cycle, isothermal heating and expansion, is accomplished when an area of gas is rotated through a first quarter section having a heating element mounted thereto and where the area in which the gas is contained increases. The second stage of the Stirling cycle, constant volume cooling, is accomplished when the area of gas remains constant as it is rotated through a second quarter section adjacent to the first quarter section. The second quarter section has a larger radius and therefore a larger area than the first quarter section. The third stage of the Stirling cycle, isothermal cooling and compression, is accomplished when the area of gas is rotated into a third quarter section having a cooling element mounted thereto and the area in which the gas is contained diminishes. The fourth stage of the Stirling cycle, constant volume heating, is accomplished when the area of gas is rotated into a fourth quarter section having a smaller radius and smaller area than the third quarter section and the area remains constant.

Thus, the induced temperature difference is converted from thermal energy into mechanical energy. This rotational energy may be utilized by connecting equipment to the center of the rotor. Alternatively, the heating and cooling elements may be removed and a driver may be connected to the rotor for rotating the rotor. Thus, a rotational motion is introduced by the driver which is converted into thermal energy. The thermal energy is released and realized at the first and third quarter sections. This thermal energy may be utilized by systems requiring above or below normal temperatures.

Turning now to the drawings, in which similar reference characters denote similar elements throughout the several views, FIGS. 1-9 illustrate the Piston-Free Stirling Cycle Engine according to invention principles.

The geometry of the enclosed housing is defined by quarter circles. We shall then define the quarter circles using two distinct methods. First method, the most commonly known is to define a circle by distinctly defining a center and a radius. Therefore any given circle can be defined by its radius and its center point and the quarter circle being defined as one quarter of the periphery of that circle. Second method used is by defining three non-linear distinct points. Any given distinct circle can be defined as an arc going through three non-linear distinct points.

FIGS. 1 a, 1 b, 1 c are illustrative views of how the inner housing of the Piston-free Stirling cycle is composed according to invention principles. The Housing is formed from four unique quarter circles called QC1, QC2, QC3, QC4. The quarter circles are defined in relation to a horizontal axis X′X, a vertical axis Y′Y and intersection or origin O as indicated in FIGS. 1 a, 1 b and 1 c. Dashed lines are used to illustrate the full circle realizations of quarter circles QC1 and QC3. These full circle realizations help to display how the housing is defined from QC1, QC2, QC3 and QC4.

Circle C1 is shown in FIG. 1 a with its center located at the origin O with a radius R1. QC1 is a quarter of the circle C1 and shown in a solid line. QC1 starts at point A and ends at point B. QC1 also has a radius R1 and is centered about point O. Line OA extends at substantially 45 degrees from the horizontal axis OX′ and line OB extends at substantially also at 45 degrees from the axis OX, defining QC1 as the upper quarter of circle C1. Point B′ forms the intersection of Circle C1 and the horizontal axis OX. Point A′ forms the intersection of circle C1 and horizontal axis OX′. Thus, C1 may be defined by two sets of data-radius R1 and origin O or by intersection point A, intersection point B and origin O.

Circle C3 is shown in FIG. 1 b with its center located at the origin O with a radius R3. The radius R3 is larger than radius R1. Circle C3 shares the same center O with circle C1, but has a larger radius than C1. QC3 is a quarter of the circle C3 shown in thick line. Quarter circle QC3 starts at point C and ends at point D. QC3 has a radius R3 and is centered about point 0, wherein R3 is larger than R1. Line OD extends at substantially 45 degrees from the horizontal axis OX′ and line OC extends at substantially 45 degrees from the axis OX, defining QC3 as the lower quarter of circle C3. Point C′ forms the intersection of circle C3 and the horizontal axis OX. Point D′ forms the intersection of circle C3 and horizontal axis OX′. Thus, C3 may be defined by two sets of data—radius R3 and origin O or by intersection point C, intersection point D and origin O.

Point E is located on the axis X′X at a mid point or mid distance between points B′ and C′. Point F is located on the axis X′X at a mid point or mid distance between points A′ and D′. (See FIG. 1 b) All the following distances are equal FA′=FD′=EB′=EC′ also OA′=OB′, OF=OE, OD′=OC′

QC2 and QC4 are shown in FIG. 1 c with radius R2 and origins located at O2 and O1, respectively. A circle can be defined by three distinct non-linear points. Quarter circles QC2 and QC4 bring together quarter circles QC1 and QC3. Thus, QC2 is defined as the quarter circle formed by the following three distinct non-linear points: circle C1 axis intersection point B, circle C3 axis intersection point C and average intersection point E. Similarly, QC4 is formed by the following three non linear distinct points: circle C1 axis intersection point A, circle C3 axis intersection point D and average intersection point F. QC2 is a mirror image of QC4 with respect to the axis Y′Y. By using mathematical methods the center and radius of quarter circles QC2 and QC4 can be found solving the coordinates of the three points B,E,C and A,F,D respectively. QC2 and QC4 have the same radius R2 but share different centers 02 and 01, respectively. Centers )1 and )2 and distinct are different from center O. Thus, the housing of the piston-free Stirling cycle engine is formed by the quarter circles QC1, QC2, QC3 and QC4.

Any line going through the center O and intersecting the housing at two opposed points will have a constant distance between these two opposing points. FIG. 2 illustrates this property using line L1 and L2. Lines L1 and L2 go through the center O and intersect the housing at point (a1, b1) and (a2, b2), respectively. The distance d between points a1 and b1 is equal to distance d between points a2 and b2 (and similarly equal to the distance d between points a3 and b3). Therefore any line passing through the center O at any angle from the horizontal axis X′X will have constant length between both its intersecting points with the housing. That length remains constant and equal to d, as the sum of radii in opposing quarter circles. This property has significant implications that we will discuss further.

FIG. 3 is an illustrative view of the rotor and housing of the Piston-free Stirling Cycle Engine according to invention principles. The Piston-free Stirling Cycle Engine includes a rotor 12 which rotates within the housing 10. The Rotor 12 is of a circular disc-like shape and has spaced vanes extending into and positioned around the periphery thereof. The vanes 14 are positioned so that each one has a diametrically opposed vane 14 with respect to the origin O. Centerlines, identified by dashed lines in FIG. 3, connect diametrically opposed vanes 14. The centerlines of all vanes 14 pass through the center O of the rotor. The center of the rotor 12 is also the center O of the housing 10. Although the rotor 12 is illustrated with eight chambers, it should be understood that the rotor may contain any number of diametrically opposed chambers.

A blade 16 is slideably positioned within each vane 14, as illustrated in FIG. 4 a. Each blade 16 is connected by a connecting rod to the opposing blade located in the diametrically opposite vane. The blades 16 are positioned in pairs such that each of a pair of blades 16 is located on diametrically opposing sides of the vanes 14 in the rotor 12. Each pair of opposing blades 16 lies on a single plane. The plane formed by opposing blades 16 rotates about the center O. For all pairs of opposing blades 16, the distance from the tip of the blade 16 to the tip of the diametrically opposing blade 16 remains constant and that distance is equal to D—D being the sum of radii in opposing quarter circles. As the rotor 12 rotates, each pair of blades 16 maintain a constant tip to tip distance and maintain contact with the housing 10. It should also be noted that the plane formed by opposing blades 16 always has one point passing through the center O though that point is not fixed throughout the revolution.

FIG. 4 b is an illustrative view of the rotor 12 and housing 10 of the Piston-free Stirling Cycle Engine according to invention principles wherein the vanes 18 extend through a diameter of the rotor 12. As previously discussed in FIG. 4a, the diameter within the housing 10 remains constant around the entire housing 10 and the edge to edge distance of opposing blades 16 within the same pair of vanes 14 remains constant. Opposing blades 16 may be connected by a solid link or may be replaced with a single extended blade 20 spanning the diameter of housing 10. The extended blade 20 resides in each extended vane 18 with each end of each extended blade 20 reaching an inner contour of the housing 10. As rotor 12 rotates, each extended blade 20 slides within its respective extended vane 18 while maintaining contact on opposing tips with the inner side of the housing 10.

FIG. 5 is an illustrative view of the rotor 12, housing 10 and blades 16 of the Piston-free Stirling Cycle Engine according to invention principles. The housing 10 is made up of four regions (22, 24, 26 and 28). Each blade 16 is slidably positioned within a vane 14. The blades 16 are positioned in pairs such that each of a pair of blades 16 is located within diametrically opposing vanes 14 in the rotor 12. Each pair of opposing blades 16 lies on a single plane rotating about the center O. For all pairs of opposing blades 16, the distance from the tip of the blade 16 to the tip of the diametrically opposing blade 16 remains constant and that distance is equal to d. d is the sum of the radii in opposing regions (22 and 26 or 24 and 28). As the rotor 12 rotates, each pair of blades 16 maintain a constant tip to tip distance and maintain contact with the housing 10. However, a single blade 16, within a pair of blades 16, slides in and out of the rotor 12 during the rotation of the rotor 12. As a blade 16 is rotated through a first region 22, the blade 16 slides outwards with respect to its vane 14. As a blade 16 is rotated through a second region 24, the blade 16 remains in a constant position, not sliding inwards or outwards with respect to its vane 14. As a blade 16 is rotated through a third region 26, the blade 16 slides inwards with respect to its vane 14. As a blade 16 is rotated through a fourth region 28, the blade 16 remains in a constant position, not sliding inwards or outwards with respect to its vane 14. Accordingly, if a single blade 16 belonging to a pair of blades 16 slides inwards with respect to its vane, the second blade 16 of the pair of blades 16 will slide outwards with respect to its vane—the converse also holds true.

FIG. 6 is an illustrative view of the Piston-free Stirling Cycle Engine according to invention principles. The space 38 between the rotor 12 and the housing 10 is filled with gas. The gas is divided into compartments 38, defined by two adjacent blades 16. To reproduce the Stirling cycle process, heating element 30 and cooling element 32 are positioned on opposing sides of the housing. Heating element 30 increases the temperature of the gas in the compartments 38 as they pass through the first region 22. Due to this isothermal increase in temperature, the gas in the first region 22 sealed between the rotor 12, the Housing 10 and two adjacent blades thus seeks to expand into an area of larger volume. The first region 22 is of an asymmetrical and increasing shape, wherein the volume increases as the rotor 12 moves in a counter clockwise direction within the housing 10. Thus, as the gas in the first region 22 expands, force is exerted on the rotor 12 to turn in a counter clockwise direction. This force of expansion causes the compartments of the first region 22 to rotate towards the second region 24. The compartments 38 are rotated into the second region 24 and remain at a constant volume. It should be understood that the orientation herein is listed as counter clockwise for illustration purposes only and alternatively the rotor may rotate in a clockwise direction if the heating element 30 is positioned on the opposite side adjacent to the third region 26. As the rotor 12 rotates, the compartments 38 along with the gas contained therein are rotated with the rotor in the direction of rotation.

When the temperature of the gas in the first region 22 is increased by external heating element 30, causing the rotor 12 to rotate, the compartments 38 of gas within the first region 22 expand into a second region of larger but constant volume 24. Simultaneously, the pre-expanded compartments 38 of gas which were previously in the second region 24 are rotated into a third region 26. The third region 26 is of an asymmetrical and decreasing shape. The volume of a compartment 38 in the third region 26 decreases as the rotor 12 is rotated in a counter clockwise direction. Thus, as the compartments 38 of gas in the second region 24 are rotated into the third region 26 they are compressed. This compression causes the temperature of the gas to increase. This increase in temperature is balanced by cooling element 32. Cooling element 32 decreases the temperature of the gas in the compartments 38 as they pass through the third region 26. Simultaneously, the compressed gas in the compartments previously in the third region 26 is rotated into a fourth region of smaller but constant volume 28. The compressed gas in the compartments previously in the fourth region 28 is simultaneously rotated into the first region 22 where its temperature is increased due to the heating element 30 and the Stirling cycle begins anew for the compartments rotated into the first region. Therefore, each region (22, 24, 26 and 28) of the housing 10 is responsible for a respective phase of the Stirling cycle.

The second 24 and the fourth 28 regions require a direct or indirect internal heat exchange. In existing Stirling engines, heat exchange is performed by a regenerator (not shown). Alternatively, the heat exchange may be performed by a pipe connected and filled with. In FIG. 6 an internal heat exchange medium 36 is used to exchange heat between the heated expanded compartments of gas 38 in the second region 24 and the compressed cooled compartments 38 of gas in the fourth region 28. This raises the temperature of the gas in the fourth region 28, thereby pre-heating the gas before entering the first region 22.There is no mass exchange of gas between the second 24 and fourth 28 regions, only a heat exchange there between.

A driver 34 is connected to the center of rotor 12, located at center point 0 (as illustrated in FIG. 2) for rotating the rotor 12. As described above, thermal energy is applied to the first region 22 of housing 10 to encourage the rotation of rotor 12. The rotational energy of rotor 12 is utilized using the driver 34. Driver 34 may be connected to a generator or other device as is common in the art. Thus, thermal energy is converted into mechanical energy. The mechanical energy can in turn be connected to a generator for conversion to electricity, to hydraulic pumps compressors or for any other useful means.

FIG. 7 is an illustrative view of the Piston-free Reverse Stirling Refrigeration Cycle Engine according to invention principles. The Reverse Stirling cycle may be utilized to produce refrigeration or heat. Driver 34 is connected to the center of rotor 12. Driver 34 may be connected to a motor or other device as is common in the art to provide rotational force to the rotor 12. The rotational force provided by the driver 34 rotates the rotor 12, thereby also rotating the compartments 38 and gas contained therein through the first 22, second 24, third 26 and fourth 28 region. Thus, the cooled gas in the second region 24 is rotated counter clockwise into a third region 26, compressing the gas. This compression of the gas, as it enters the third region 26, causes the temperature of the gas to rise. The compressed gas in the third region 26 is rotated into a fourth region 28. An internal heating exchange medium 36 allows for the compressed gas in the fourth region 28 to undergo an internal heat exchange with the heated gas in the second region 24. The gas in the fourth region 28 is then rotated into the first region 22 where it is able to expand. This expansion requires heat. Therefore, the first region 22 absorbs heat or heat is removed from the environment. The expanded gas in the first region 22 is then rotated into the second region 24 where it undergoes an internal heat exchange with the cooled compressed gas located in the fourth region 28. Thus, rotational energy is converted into thermal energy thereby producing a refrigeration cycle.

FIG. 8 is a flow diagram of the Piston-free Reverse Stirling Cycle Engine according to invention principles. The Piston-free Stirling Cycle Engine is used to convert thermal energy into rotational energy. As discussed in step S100, heat is applied to compartments positioned within a first quarter section of the housing containing gas thus initiating the rotation of the rotor as stated in step S110. The rotation of the rotor in step S110 causes compartments of gas in a section of the housing to rotate into an adjacent section of the housing. Each section of the housing initiates a step of the Stirling cycle. Thus, each compartment undergoes one of the four stages of the Stirling cycle as the compartments rotate through the four sections of the housing.

Compartments of warm compressed gas are rotated into a first section of increasing volume as described in step S 120. As the rotor rotates, thus moving compartments of gas from the fourth section into the first section, a heat source increases the temperature of the compartments of gas. This rise in temperature causes the gas to expand. The expansion of the gas causes the rotor and thus the compartments of gas in the first section to rotate into a second larger section of constant volume as stated in step S130. The heated expanded compartments of gas in the second section undergo an internal heat exchange with cooled compressed compartments of gas in a fourth section. Thus, the heated expanded compartments of gas are cooled at a constant volume in the second section. The cooled expanded compartments of gas are then rotated into a third section of decreasing volume as discussed in step S140. As the cooled expanded compartments of gas are rotated into an area of decreased volume, the compartments of gas are compressed. This compression of gas causes the compartments of gas to give off heat as they enter the third section. To offset this increase in temperature, a cooling source is operable to decrease the temperature of the compartments of gas in the third section. The cooled compressed compartments of gas are then rotated from the third section into a fourth smaller section of constant volume in step S150. The cooled compressed compartments of gas in the fourth section undergo an internal heat exchange with the heated expanded compartments of gas in the second section. Thus, the cooled compressed compartments of gas are heated at a constant volume in the fourth section. The heated compressed compartments of gas are then rotated into the first section of increasing volume as stated in step S120 and the Stirling cycle begins anew. This process repeats until heat ceases to be applied in step S100. each set of compartments passes through a respective cycle of the Stirling cycle offset by one cycle from the immediately adjacent sets of compartments and offset by two cycles from the opposing set of compartments.

FIG. 9 is a flow diagram of the Piston-free Reverse Stirling Cycle Engine according to invention principles. The Piston-free Stirling Cycle Engine according to invention principles may be used to convert rotational energy into production of refrigeration. The process begins in step S200 with the rotation of the rotor. The rotation of the rotor in step S200 causes compartments of gas to rotate from one section of the housing into an adjacent section of the housing. Each section of the housing initiates a step of the Stirling cycle. Thus, each compartment of gas undergoes the four steps of the Stirling cycle offset from one another as they rotate through the four sections of the housing.

Gas is rotated into a first section of increasing volume as stated in step S210. This is an isothermal expansion. Heat is absorbed during isothermal expansion of the gas. This absorption of heat causes a cooling effect by the first section. The heated expanded compartments of gas are rotated into a second larger section of constant volume as discussed in step S220. The heated expanded compartments of gas of the second section undergo an internal heat exchange with cooled compressed compartments of gas in a fourth section. Thus, the heated expanded compartments of gas are cooled at a constant volume in the second section. The cooled expanded compartments of gas are then rotated into a third section of decreasing volume as described in step S230. As compartments of gas enter the third section of decreasing volume, the gas is compressed. The compression of gas increases its temperature. Thus, the compartments of gas release heat as they are compressed in the third section. In that section heat must be removed from the engine by means of a heat exchanger or radiator. The compressed gas compartments are rotated into a fourth smaller section of constant volume as stated in step S240. The compressed compartments of gas of the fourth section undergo an internal heat exchange with the heated expanded compartments of gas in the second section. Thus, the cooled compressed compartments of gas are heated at a constant volume in the fourth section. The heated compressed compartments of gas are then rotated back into the first section of increasing volume as described in step S210 and the Reverse Stirling cycle begins anew until the rotor ceases to be rotated in step S200. The usual thermodynamic convention is followed in which heat is removed from the environment exposed to portion of engine of increasing gas volume S210 and heat is expelled into the environment exposed to portion of the engine of decreasing gas volume as shown in step S230. Internal heat exchanges are crucial for proper function of the refrigeration cycle. This is accomplished by exchanging heat, thereby removing heat from the constant Volume Cooling section S220 and exchanging it with the constant volume heating section S240.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit according to invention principles.

Without further analysis, the foregoing will so fully reveal the gist according to invention principles that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. 

1. An energy conversion device comprising: a housing including: a first section of increasing volume; a second section of decreasing volume, said second section positioned opposite said first section; a third section of constant volume positioned between a first end of said first section and a first end of said second section; and a fourth section of constant volume positioned between a second end of said first section and a second end of said second section.
 2. The energy conversion device of claim 1, further comprising of a rotor positioned within said housing.
 3. The energy conversion device of claim 2, wherein said rotor contains spaced vanes positioned around the periphery.
 4. The energy conversion device of claim 3, wherein blades are slidably positioned within said vanes and extend to make contact with an inner wall of said housing, wherein said blades maintain contact with the housing as said rotor rotates thereby sealing a gas between said housing, adjacent blades and said rotor.
 5. The energy conversion device of claim 4, wherein gas is located in the area between each of said blades.
 6. The energy conversion device of claim 2, wherein said rotor is connected to a driver.
 7. The energy conversion device of claim 1, wherein each of said sections makes up a quarter of said housing.
 8. The energy conversion device of claim 1, wherein a heating element is positioned adjacent said first section.
 9. The energy conversion device of claim 1 wherein a cooling element is positioned adjacent said second section.
 10. The energy conversion device of claim 1, wherein said first and second sections are arcuit in shape and share a common center.
 11. The energy conversion device of claim 1, wherein said third and fourth sections are arcuit in shape and have radii identical in length.
 12. A method of converting thermal energy into rotational energy by rotating a rotor within a housing, the rotor and housing forming a plurality of chambers within the housing, comprising the activities of: providing gas within each of the plurality of chambers; applying heat to a first set of the plurality of chambers positioned within a first section of the housing; expanding the gas within the first set; rotating the rotor in response to the expanding the gas within the first set, wherein rotation of the rotor causes: the first set to move into a second section of constant volume within the housing and an adjacent set of chambers to move into the first section to be heated; upon heating of the second set, the first set is caused to move into a third section of decreasing volume within the housing, the second set moves into the second section and a third set of chambers adjacent to the second set moves into the first section to be heated; upon heating of the third set, the first set is caused to move into a fourth section of constant volume within the housing, the second set moves into the third section, the third set moves into the second section and a fourth set of chambers adjacent to the third set moves into the first section to be heated; and upon heating of the fourth set, the first set is caused to move into the first section of increasing volume within the housing, the second set moves into the fourth section, the third set moves into the third section and the fourth set moves into the second section.
 13. The method of claim 12, wherein the rotor contains spaced chambers positioned around the periphery.
 14. The method of claim 13, wherein blades are slidably positioned within the chambers and extend to make contact with an inner wall of the housing.
 15. The method of claim 13, wherein chambers positioned within the third section of the housing are cooled isothermally by a cooling element.
 16. The method of claim 13, wherein chambers positioned within the second and fourth sections of the housing undergo an internal heat exchange
 17. The method of claim 13, wherein a driver is connected to the rotor to utilize the rotational energy induced by the rotation of the rotor.
 18. A method of converting rotational energy into thermal energy or by producing refrigeration by rotating a rotor within a housing, the rotor and housing forming a plurality of chambers within the housing, comprising the activities of: providing gas within each of the plurality of chambers; expanding the gas within a first set of the plurality of chambers positioned within a first section of the housing; rotating the rotor, wherein rotation of the rotor causes: the first set to move into a second section of constant volume within the housing and an adjacent set of chambers to move into the first section to be expanded; upon expanding the second set, the first set is caused to move into a third section of decreasing volume within the housing, the second set moves into the second section and a third set of chambers adjacent to the second set moves into the first section to be expanded; upon expanding the third set, the first set is caused to move into a fourth section of constant volume within the housing, the second set moves into the third section, the third set moves into the second section and a fourth set of chambers adjacent to the third set moves into the first section to be expanded; and upon expanding the fourth set, the first set is caused to move into the first section of increasing volume within the housing, the second set moves into the fourth section, the third set moves into the third section and the fourth set moves into the second section.
 19. The method of claim 18, wherein a driver is connected to the rotor to provide rotational energy.
 20. The method of claim 18, wherein the rotor contains spaced chambers positioned around the periphery.
 21. The method of claim 19, wherein blades are slidably positioned within the chambers and extend to make contact with an inner wall of the housing.
 22. The method of claim 18, wherein chambers positioned within the second and fourth sections of the housing undergo an internal heat exchange 